Background: Ileus can be the consequence of multiple factors, including an operation, a side effect of drugs or the result of an obstruction requiring direct operative correction. Although auscultation for bowel sounds is routinely performed in the ICU and a well-established part of the physical examination in patients, its clinical value remains largely unstudied.
Methods: To determine whether auscultation for bowel sounds helps in clinical decision-making in ICU patients with ileus, a literature search of PubMed, Embase and Cochrane was performed to study the diagnostic value of auscultation for bowel sounds. Results: The inter-observer variability for the assessment of the quantity, volume and pitch of bowel sounds was high, with a moderate inter-observer agreement for discerning postoperative ileus, bowel obstruction and normal bowel sounds (kappa value 0.57). The intra-observer reliability of duplicated recordings for distinguishing between patients with normal bowels, obstructed bowels or postoperative ileus was 54%. No clear relation between bowel sounds and intestinal transit was found. Sensitivity and positive predictive value were low: 32% and 23% respectively in healthy volunteers, 22% and 28% in obstructive ileus, and 22% and 44% in postoperative ileus. Conclusions: Auscultation with the aim to differentiate normal from pathological bowel sounds is not useful in clinical practice. The low sensitivity and low positive predictive value together with a poor inter- and intra-observer agreement demonstrate the inaccuracy of utilising bowel sounds for clinical decision- making. Given the lack of evidence and standardisation of auscultation, the critically ill patient is more likely to benefit from abdominal imaging.